1. Field of the Invention
The present invention relates to the field of automatic telephone answering devices, and is more particularly directed to a telephone number coding device requiring that a caller dial a special number code, in addition to a regular telephone number, in order to actuate a ring signal for a telephone attached to the device.
2. Description of the Prior Art
With the advent of dual tone multi-frequency (Touch Tone.RTM.) telephone systems, it is possible to utilize a telephone keypad for more than simply dialing a telephone number. Once a regular telephone number has been dialed and the connection completed, additional code numbers can be dialed to accomplish such things as computer access, paging, electronic funds transfer, alternative long distance calling, and remote control of alarms, locks, electrical appliances, and surveillance systems. Although the current state of the art allows virtually the entire planet to be linked with our personal telephone, whether wired or wireless, there are times when the phone's incessant ringing is no longer welcomed. Many of the calls are wrong numbers, solicitors, salesmen, or simply those to whom we do not wish to speak. Even with an "unlisted" number, many of the nuisance calls manage to get through. The telephone rings again, and we find ourselves in George Orwell's world of 1984: ". . . Always the eyes watching you and the voice enveloping you. Asleep or awake, working or eating, indoors or out of doors, in the bath or bed--no escape . . . "
One welcome telephone advancement is the modular plug. At least one can pull the plug to physically disconnect the phone. Or one can install a special switch to silence the ring. Although these methods do offer the telephone subscriber some degree of control over his phone, important calls can be missed when the telephone is disconnected or silenced. To assure receipt of wanted calls without becoming harried by nuisance calls, other alternatives can be used. An obvious one is the telephone answering device which is probably the best known and most widely used telephone accessory. Users of an answering machine can screen all calls by having the machine record all incoming messages. After rewinding the tape, the machine user can then listen to each message and decide which calls he wishes to return. The disadvantages here are that the recording tape must be reviewed before selected calls can be returned, and non-local calls will be paid for by the machine user when any of these non-local calls are returned. Some types of answering machines allow the user to monitor all incoming calls through a speaker, whereby the answering machine is immediately disabled if a call is personally answered. A disadvantage to this often helpful feature is that the machine user must remain physically near the answering machine in order to monitor incoming calls on the machine's speaker.
An additional alternative can be provided in the form of a telephone number coding device. The device can be plugged into a normally used telephone line modular jack, and the telephone, in turn, plugged into a modular jack provided on the rear surface of the device. In use the device responds only to a special number code of the user's choosing. In effect, the device causes its attached telephone to become "hidden" from all who do not know the special code, and can, therefore, convert a standard telephone to a "hidden telephone," or "cryptophone." The special number code required by the coding device can consist of any reasonable number of digits which must be dialed by the caller after a regular telephone number has been dialed and a connection completed. If a special number code is correctly dialed, the coding device is actuated and notifies the user that a call is being received. Only at this time will the person being called be aware of an incoming call, since connection of a telephone to the telephone number coding device automatically disables the ringer mechanism of the telephone. The required code number, therefore, provides the device user with a secret, "unlisted" telephone number, regardless of whether or not the telephone is already unlisted with the telephone company. Thus, the telephone subscriber obtains total control over his telephone by receiving calls from only those to whom he has revealed the special telephone number code. If the coding device owner so desires, the special code can be easily and instantly changed to halt all calls received via a previous code. It is, therefore, a general object of the present invention to provide a telephone number coding device which converts a standard telephone to a "cryptophone," or "hidden telephone" by requiring that a special digital code be dialed subsequent to a regular telephone number, in order for the telephone to "ring."